This invention relates to a video security system for monitoring a number of premises simultaneously; and, more particularly, to a work station for such a system by which information (video, audio, and data) can be displayed for a system operator responsible for alerting authorities of an intrusion at a premises and who relies on the displayed information in determining whether or not authorities are notified.
Previously, security systems protected a building using make/break contacts strategically placed at doors, windows, and other potential entry points. When a contact is broken and an alarm is sounded or relayed to a central control station located within the building, nearby to the building, or remotely to a central control station of the security company. Besides make/break sensors, security companies used P.I.R. (passive infra red) sensors which sense heat differences caused by animate objects such as humans or animals, vibration sensors which, when placed upon a window for example, detect when the window is broken, and microwave sensors. As with the make/break sensors, when any one of the sensors indicates a detection, a system alarm is indicated. The alarm is also given if an alarm unit in the building to which the sensors are connected senses that the path to a sensor is interrupted or broken.
With these alarm systems, all the receiver of an alarm knew was that an alarm had occurred. The system operator had no other knowledge by which he can determine if an alarm signals the presence of a real intruder, or if it was a false or unwanted alarm. Because sensors were notorious for going off during inclement weather (they are sensitive to large electromagnetic fields such as will occur during lightning conditions, etc.), or were triggered by the presence of animals, etc., the resulting false or unwanted alarms detrimentally effected the efficiency and operation of the security system.
While the situation was annoying when a false or unwanted alarm was relayed to a local monitoring station, the situation became even worse when the alarm was to a security company's remote central station. Here, operators had to use their experience of the particular circumstances surrounding the alarm (i.e., local weather conditions, past occurrences at that particular site, etc.), to determine whether or not the alarm is real. If their knowledge and experience told them the alarm signified an actual intrusion, they had to relay the alarm to the local police for that site so the police can conduct a further investigation.
There are numerous examples of an alarm system either not working, or being rendered ineffective, because of the number of false or unwanted alarms to which authorities had to react. Once the authorities refused to investigate reported alarms for a premises, the premises was essentially not protected. Over the years, situations resulting from false and unwanted alarms have continued to worsen. Now, police often require confirmation or evidence of an intrusion before investigating, or else they will give priority to those situations where they have greater certainty an intrusion has occurred. Security system companies first addressed this issue by providing an audio (or "listening-in") capability to the system. This enabled the monitor to hear actual movement on the premise (the sound of voices, glass breaking, cabinets or drawers being opened, etc.), with this information also being relayed to the authorities. Now, the security industry has begun to extensively use video cameras to constantly monitor premises. While this solves certain of the problems discussed above, new problems have arisen. One shortcoming of camera surveillance is the need for a continuously connected communication channel for the sensor (camera), with an operator having to must continuously monitor the video. Some systems have attempted to combine video with another sensing mechanism, P.I.R., for example, so that actuation of the video is controlled by the other sensor first sensing the presence of an intruder. To further control costs, the cameras are often slow scan cameras whose output is compressed onto POTS (plain old telephone system) lines (typically using 28.8k modems) with transmission rates of 1 frame of video over a 1-5 second interval.
At the monitoring site, an operator now has two problems to confront. First, because the frame rate is slow, what the operator sees is not what is necessarily occurring at that moment. But, more importantly, most of the time the operator will see nothing at all out of the ordinary. Yet, the operator must maintain a constant vigilance. This is a serious problem because it has been estimated that after watching a security system camera observing an unchanging scene for as little as 5 minutes, an operator's performance diminishes rapidly to the point where the operator is essentially ineffective after 30 minutes. One result of this, of course, is that unwanted alarms still occur. So, up until now, the only real advantage video monitoring offered was that should an intrusion occur and should the operator notice it, then the relayed information sent to the local police got high priority because of the certainty of the situation.
The video security system of the present invention overcomes these problems in part by providing a system operator live images of an intrusion, not causing him to waste his time of "crying wolf" because of false and unwanted alarms, and by providing a level of surveillance not obtainable even using guards on site. It is now possible, as described hereinafter, to relay definitive information to the local police of an intrusion, as well as capture, maintain, and transmit images of the intrusion to the police or other authorities. It is also possible to eliminate false alarms, regardless of their causes.
In co-pending U.S. patent application Ser. Nos. 08/772,731; 08/757,838; 08/771,991; and 08/772,595; the teachings of which are incorporated herein by reference, there is described a system and method for continuously viewing a scene to detect the presence of an intruder with a very low probability of false alarms and with a high probability of detection; authenticating an image of the intrusion, and relaying the authenticated image from the protected site to a monitoring site. The ability to determine, at the monitoring site, whether or not an intrusion has occurred, now removes from the human operator of the system the initial responsibility of determining whether an intrusion results from a new human presence, or otherwise. This, in turn, eliminates the need for the human operator to continuously monitor all of the cameras on the premises of the sites being protected. Also, because detection and recognition for each premises is conducted on-site at that premises, there is no need for a continuous communication path between the premises and a central station of the system. When a path is established, high frame rate and high quality video is transferred from the site to the operator so the operator can evaluate the video and concur with the evaluation an intrusion has occurred. Further, once an intrusion is detected, high resolution samples ("snapshots") of the video are taken and supplied to the alarm system operator at the central station. These samples are transferred using lossless compression techniques and are authenticated for later admittance into court for prosecution purposes. What is now required is a workstation at which an operator can timely display images of an intrusion, live images of the scene of the intrusion, audio from the scene, as well as pertinent data about the premises. This latter might include a history of previous intrusions, monitoring history for the premises, and other significant information.